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Anatomy of the Skin

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Facts about the skin

The skin is the body's largest organ. It covers the entire body. It serves as a protective shield against heat, light, injury, and infection. The skin also:

Regulates body temperature

Stores water and fat

Is a sensory organ

Prevents water loss

Prevents entry of bacteria

Acts as a barrier between the organism and its environment

Helps to make vitamin D when exposed to the sun

Your skin takes on different thickness, color, and texture all over your body. For example, your head contains more hair follicles than anywhere else. But the soles of your feet have none. In addition, the soles of your feet and the palms of your hands are much thicker than skin on other areas of your body.

The skin is made up of 3 layers. Each layer has certain functions:

Epidermis

Dermis

Subcutaneous fat layer (hypodermis)

Epidermis

The epidermis is the thin outer layer of the skin. It consists of 3 types of cells:

Squamous cells. The outermost layer is continuously shed is called the stratum corneum.

Basal cells. Basal cells are found just under the squamous cells, at the base of the epidermis.

Melanocytes. Melanocytes are also found at the base of the epidermis and make melanin. This gives the skin its color.

Dermis

The dermis is the middle layer of the skin. The dermis contains the following:

Blood vessels

Lymph vessels

Hair follicles

Sweat glands

Collagen bundles

Fibroblasts

Nerves

Sebaceous glands

The dermis is held together by a protein called collagen. This layer gives skin flexibility and strength. The dermis also contains pain and touch receptors.

Subcutaneous fat layer

The subcutaneous fat layer is the deepest layer of skin. It consists of a network of collagen and fat cells. It helps conserve the body's heat and protects the body from injury by acting as a shock absorber.